Applicant's assignee, Speakman Company, is a pioneer in the field of adjustable spray pattern showerheads. These are sold under the ANYSTREAM trademark throughout the world. Numerous patents have been obtained by Speakman describing details of such showerheads. These include: McLean U.S. Pat. No. 3,013,729; Fraser U.S. Pat. No. 3,065,917; Roman et al U.S. Pat. No. 3,373,942; Fiorentino U.S. Pat. No. 3,383,051; and Lagarelli U.S. Pat. No. 4,117,979. Another type of adjustable spray showerhead is illustrated in Stacey U.S. Pat. No. 3,563,469.
One of the problems encountered with these prior art showerheads is loss of spray pattern integrity at low flow conditions currently mandated by state law as a water conservation measure. A national standard (ANSI-ASME A112.8.1 M-1994) has recently been adopted pursuant to the Energy Policy and Conservation Act of 1992 that limits flow through showerheads to 2.5 gallons per minute. A comparable standard has been adopted in Canada (CAN/CSA-B125-M89). Under low flow and low pressure conditions, the spray pattern in some of the prior art showerheads tends not to fill all of the grooves in the plungers of the showerheads described above. This causes erratic and uneven spray patterns. Most showerhead users want, and expect, a uniform spray of even intensity under all flow conditions.
Another problem with some of the showerheads described above is clogging of the grooves in the plungers. This clogging is aggravated where a hard (mineral laden) water supply is used. The buildup of mineral deposits can get so bad that the plungers actually "freeze" in position, thereby disabling, or limiting, the spray adjustment feature of the showerhead. Various approaches to resolution of this problem have been proposed, including use of specific materials or some form of wiping action across openings in the faceplate of a showerhead.
Another aspect of water conservation is the water lost during the non-rinse cycles of a showering experience. A shower spray is usually not wanted during the soap-up or hair shampooing part of the total showering cycle. Water flow during those portions of the shower is essentially wasted. Thus, there is a need for a showerhead that can reduce, or shutoff, water flow when not wanted, without affecting the spray patterns when showering is resumed. Although shutoffs are available, they are typically located upstream of the showerhead in the water supply piping. As such, they are hard to locate and operate by a typical user who may have his or her eyes shut to avoid the sting of soap or shampoo. Those shutoffs that are located on or in the showerhead are typically linked to the showerspray mechanism so that the spray pattern must be readjusted after each water shutoff.
Another disadvantage of existing showerheads is that most grooves used to create a spray pattern are uniform in cross section at any given plane taken through the showerhead. In other words, although the grooves may vary in depth as measured along the axis of the showerhead, few showerhead designers have paid attention to varying the placement of grooves and groove depth around the periphery of the showerhead opening to avoid overlap in spray patterns.
Numerous attempts have been made to provide a vibratory spray in showerheads and other water discharge devices. Most devices used to create a vibratory spray utilize moving parts such as a turbine or off center wobble-plate to achieve the desired periodicity in the water spray. These parts are subjected to considerable wear and often cease to function when mineral deposits interfere with their freedom of movement.
Many showerheads are designed with one, maybe two, of the features discussed above: variable spray patterns, shutoff valve, vibratory spray, controlled spray pattern, self cleaning spray openings. Few have all of these features and none are designed to permit production of showerheads with a variable assortment of such features.